138 ANIMAL INDIVIDUALITY [CH. 



tissues it has gone perhaps still further : here the 

 cells, surrendering all separateness of existence, have 

 fused to form mere sheets of continuous protoplasm 

 studded with nuclei. These syncytia are only the 

 final outcome of a process whose beginnings we saw 

 in Volvox and Haplozoon the connection of the 

 separate cells by means of strands of protoplasm 

 passing from one to another. These connections 

 seem to exist in all multicellular green plants, and 

 have now been demonstrated in a great number of 

 animals 1 . Many zoologists indeed believe that the 

 fine endings of the nerve-fibrils are always in direct 

 protoplasmic continuity with the organ they supply. 



It is worth remembering that the actual history 

 of every individual runs roughly parallel with what 

 we know of the history of the race. Those who 

 cannot bring themselves to believe that the ancestor 

 of a nerve-cell, for instance, was once independent 

 and capable of all the functions of separate existence, 

 often do not consider that every nerve-cell started its 

 life simple, rounded, and undifferentiated, only later 

 throwing out its complex branching processes, and 

 later yet coming into protoplasmic continuity with 

 other cells, originally far distant in the body (Fig. 14). 



In many animals indeed every individual epi- 

 tomizes in its own the history of the race. Starting 

 as a fertilized ovum, an individual of the first grade, 



1 See Dobell (5) for facts and references. 



